Mavic Pro Battery Mod

[CyberNate]

How are the motors after a windy flight like that? Are they warm/hot?

Lightly warm, not bad at all. That's the first thing I check. The batteries are also just barely warm, as the current is distributed across all of them. The mavic battery is much cooler than it would normally be for a similar flight.

 

[Xcel]

That's interesting, probably extending the life of the Mavic battery because you're not discharging it as fast as normally.

Sorry if you answered this already but are you planning on always using the extra batteries? I'm interested in the mod but I'm gonna see how the long term test goes first

 

[CyberNate]

That's interesting, probably extending the life of the Mavic battery because you're not discharging it as fast as normally.

Sorry if you answered this already but are you planning on always using the extra batteries? I'm interested in the mod but I'm gonna see how the long term test goes first

No, not planning on using it all the time. I just like to tinker and find the limits. I have the controller amplified with dual 3W amps and FPVLR antennae as well. All this stuff makes it cumbersome when getting ready to fly. I'm quite happy with the Mavic in stock form and actually looking to acquire a stock controller to have easy quick flights.

 

[MacIak]

No, not planning on using it all the time. I just like to tinker and find the limits. I have the controller amplified with dual 3W amps and FPVLR antennae as well. All this stuff makes it cumbersome when getting ready to fly. I'm quite happy with the Mavic in stock form and actually looking to acquire a stock controller to have easy quick flights.

Thanks mate for all this testing and efforts, great job. Paving way to others..
I have to agree it takes more preflight time yet still it's nice to know some acceptable limits. Got a nice bag yesterday for €25 by the way. 1.5x the size of the orig flymore bag but it accomodates everything needed incl modded tx without the squeezing. (ok, not yours. Your remote looks like "chappie" now )

 

[Xcel]

No, not planning on using it all the time. I just like to tinker and find the limits. I have the controller amplified with dual 3W amps and FPVLR antennae as well. All this stuff makes it cumbersome when getting ready to fly. I'm quite happy with the Mavic in stock form and actually looking to acquire a stock controller to have easy quick flights.

Haha sounds like a fun setup

 

[Kingkong]

I received my battery mod today. Unfortunately after waiting for more than 1 month, they sent me the V1 mod with the splitter cable instead of V2 which has 2 plugs directly on the battery connector. I wanted V2 for simplicity and less weight. The V1 mod is very heavy. Oh well.

I went ahead and tested the mod with a pair of regular 1500mah lipos as I haven't received my 3000mah LiHV batteries yet. Lipos are not a good match for the Mavic as I saw 4.33V/cell on the Mavic after turning it on and then I connected my lipos which are at 4.18V/cell. This is wasted energy with the discrepancy and it was noticed in the first 10% of battery consumption which went quickly, in fact I was at 96% by take off after some fiddling around. It's important that the external batteries have a similar voltage to avoid any current flow between the batteries. The mod has no diodes to protect against reverse current flow.

Anyway, the Mavic flew fine, but it does use 40% "Power" on the tachometer just for hovering. Normally that should be your ideal RPM for efficient cruise speed. Anyway, I found that once you get up to speed, there is more lift available and you can cruise along at 26mph or so at around 40 to 50% RPM "Power".

Normally when I fly these distance runs, I fly in P mode with Obstacle Avoidance off. This is normally the efficient speed at around 29 to 32 mph depending on the wind. I see that this is no longer optimal with the battery mod. The Mavic will go the same speed as without the mod, but it's ramping up the RPM "Power" far too high. Electric motors waist energy when they are turning higher than optimal RPMs. This means that for a proper distance run, you will need to use sport mode and find the green/blue intersection to get the optimal RPM. On this run, I just did the normal P mode with full stick. I got just under 60,000 feet distance (51,000 of it for a distance run out and back) with 15% battery remaining and 23:40 time on battery. I took off with only 96%. The flight was into a 5-7mph wind.

Certainly the batteries will do MUCH better if try this again and use sport mode tachometer to regulate the power. I expect the cruising speed to be around 26 for this load. My arriving batteries are 50% heavier, so it's be interesting if I can actually run the motors in the optimal zone and achieve enough lift and speed.

The batteries added around 7-8 minutes over what I'd get without the mod, but that is because the motors were turning near sport mode RPM even though I was flying in P mode. Sport mode full power is VERY inefficient for the motors. I expect to see an extra 3-5 minutes or more if using optimal motor power which is around 40% on the tachometer. Anyway, the real test will be with the LiHV batteries which I believe will give stellar results with double the power of these 1500mah and only 46% more weight (376 grams vs 256 grams for 2 batteries), but I could be wrong if the RPM greatly exceeds 50% power just for cruise speed. We shall see.

This might be a noob question but how do u determine the rpm the motors are running at in flight?

 

[CyberNate]

This might be a noob question but how do u determine the rpm the motors are running at in flight?

In sport mode there is a tachometer. If you have a a non-ipad device, you need to click the upper right corner of the map to switch to tachometer view.

 

[Gh0stxSinghx]

Multistar, 3000mah LiHV. You can get them at Hobbyking.com. Having a single 4000mah is also a good option for less weight. I might go that route for simplicity.

I checked Hobbyking, What think about battery wieght - 4000mAh Lipo 244g Vs. 4000mAh LiHv 265g. Lipos are not a good match for the Mavic?

 

[CyberNate]

I checked Hobbyking, What think about battery wieght - 4000mAh Lipo 244g Vs. 4000mAh LiHv 265g. Lipos are not a good match for the Mavic?

The weight of the 4000mah lipo is incorrect. It weighs much more, like 347g. I think you're off by a 100g.

Edit: Lipos work just fine. It's just that they are heavier and have a lower voltage at full charge than the Mavic's LiHV cells. You are wasting some energy due to the voltage difference between the packs and the Mavic battery.

 

[Natedoggz]

I order the 4000 multi star lihv and asked another member to fab up some top battery clip adapters, hopefully it will work and be somewhat stable. I've got a set of reg. Lipo 1500 that I would like on top as well.

 

[cruzroy]

Hey Guys,
So I Just got done testing this mod, and I wanted to let you know my results. I know that there is a lot of controversy over whether or not these actually work. In sport mode the batteries add about 4.3 minutes of flight time, while in regular flying the batteries add about 8.2 minutes of flight time even with the extra weight. It's not a huge difference but it can come in handy. I also like the way that the Mavic flys with the extra weight, it feels more stable. The mod I constructed above weighs around 176 grams in total. After about 2 hours of testing I have experienced no problems. I did a lot of research before testing this in the field and found that the extra power on the Mavics battery cells shouldn't affect it. My guess on how this works is that the LiPo batteries charge the Mavics smart battery while it is flying, as the remote doesn't read any extra mAh or volts, another reason I have for this theory is that the LiPo's can be used for three flights before they should be charged again. I am happy to answer any questions.

How about this...............mavic mount for dual lipos,

 

[MacIak]

Ooh, nice! Anything for single battery ?

 

[Natedoggz]

I like that can i get sti on those

 

[CyberNate]

I ordered some 3m dual lock which will arrive today. With the dual lock, you don't need any extra straps. It's very strong and light. I'll replace my velcro with that for both side and top mount. Amazon has it for $20:

3M Scotch SJ4575 Dual Lock Low Profile Reclosable Fastener: 1 in. x 10 ft. (Black): Adhesive Hook And Loop Strips: Amazon.com: Industrial & Scientific

Of course having a removable mount is best, so interested to see what you guys come up with.

 

[cruzroy]

Ooh, nice! Anything for single battery ?

need a size, and i think all batteries should be near stoc lipo.....gps interference

 

[MacIak]

For size I need to get back at you (let's assume 107x35x30mm). Between 190-290 grams. Located top middle on the stock battery. Needs to be slightly "lifted" though. otherwise no access to power button and no blinkie blinkie. CG will not be optimal but it's multirotor, no 3d heli

 

[Natedoggz]

Can you add the 3d file you made of the dual battery clip?

 

[cruzroy]

For size I need to get back at you (let's assume 107x35x30mm). Between 190-290 grams. Located top middle on the stock battery. Needs to be slightly "lifted" though. otherwise no access to power button and no blinkie blinkie. CG will not be optimal but it's multirotor, no 3d heli

here you go, single lipo pack in there to......have fun

 

[Natedoggz]

I've already sent the dual lipo sti for printing, nice design, thanks for sharing the files!

 

[AMars32]

How about this...............mavic mount for dual lipos, View attachment 9650 View attachment 9651

I really like the external battery mounts as it is a lot easier and would make the process of setting up the mod slightly faster and a lot easier. Cruzroy has provided these two mounts

I like these both, the problem I see with the first one is that not all batteries will fit and you will still have to strap them down or Velcro them to the mount.

The second one seems better as the weight will be evenly divided, my only worry is that at the angle that the mount arms are at the wires from the batteries could possibly get caught up in the propellers.

I don't mean to criticize his mounts as they are very good ideas and more then I could come up with I am just suggesting some ideas.

Here is a mount from fpv customs which would be ideal if you are using a single battery.

I am thinking that a hybrid of all three of these mounts would be best. It should be able to hold two batteries pressed against the side of the craft with Velcro straps, as this is good for weight distribution and balance. Also, it could possibly have the option to put one battery on top of the Mavic using a strap. I am thinking it should be able to pop on the Mavic like cruzroy's do with an additional strap holding it in place from the bottom but ensuring it doesn't cover any sensors. I have been thinking about this for a while and I feel that would be the best possible mount.

I would love to hear some more ideas!